Oil heater



June16, 1925. 1,542,089;

- I J. PRIMROSE OIL HEATER Filed May 4, 1920 3 Sheets-Sheet 1 'OOOOOOO 00000000 E 000000 0 m 00000000 U 00000000 Q g 0000000 L0 -OOC)OOOO M'VENTOR MW Y TTORNEYS June 16, 1925.

J. PRIMROSE OIL HEATER 3 Sheets-Sheet 2 Filed May 4, 1920 IN I/EN TOR BY K24 June 16.- 1925.

J. PRIMROSE OIL HEATER Filed May 1920 s Sheets-S 3 MEN Q 4,; v E Y8 Patented dune ltd, 1925,

outrun JOHN IiRIMBOSE, OF DONGAN HILLS, NEW YORK, ASSIGNOR T0 POWER SLDECIALTY COMPANY, OF NEW YURK, N. Y.,

A CORPORATIGN @F NEW YORK.

on, HEATER,

Application filed may 4,.

To all whom it may concern:

'7 Be it known that I, JOHN Pnirrnosn, a citizen of the United States of America, residing at Dongan Hills, in the borough and county of Richmond, State of New York, have invented certain new and useful Improvements in Oil Heaters, of which the fol-' lowing is a full, clear, and exact description.

The invention forming the subject of my present application for Letters Patent is embodied in an oil heater adapted for use in what is commonly known as the topping process for refining-oils where the general practice is to heat the" oil under practically no pressure to temperatures from..l50" to 450 F. In such process the crude oil, is usually pumped from storage at a temperature of approximately 70 through what is known as a heat exchanger, where it is heated to 150 or 160, to the heater when it is heated to a temperature of about 450. From this heater the oil and vapor are piped to a separator tower where the two are separated, the vapor being piped to apparatus by which it is condensed, while the hot oil separated out is piped to the heat exchanger to supply the heat to which the crude oil is subjected on its way from storage to the heater.

Heretofore tank heaters resembling boilers without tubes and set over a furnace have been largely used, but such types of heater were uneconomical in fuel and lacked. means for properly circulating the oil. For

this reason these appliances have been largely superseded by pipe heaters, which a are not only much more economical of fuel, but permit of a positive circulation, but the advance in the construction of such heaters has not been such as to fully justify their use mainly on account of their unnecessarily large dimensions and high cost of construction and operation.

The pipe heaters heretofore used have employed extra heavy bare pipes, generally flanged at each end and connected in series by flanged U-bend iron castings. This necessitates a very large setting to accommodate the heating surface while the construction of the sidewalls is difficult because all of the flanged joints must be exposed for inspection and repair. This not only breaks up the brick work but makes it difiicult to 1920. Serial No. 378,l39.

secure an air tight setting. The flangedjoints, moreover, are objectionable because of the large number of bolts required and the presence of gaskets which invariably give trouble in their tendency to leak. In addition to this the bolts burn out and the bare pipes overheat and corrode just as they do in a superheater.

In some forms of these heaters the pipes run lengthwise of thesetting. This requires the minimum of flanged joints and U-bends,

but as the gases travel lengthwise of the tubes, ineflicient baflling is required, and the lowest pipes next the fire are apt to sag.

Other heaters are made with shorter pipes running across the setting which results in a better flow and less liability to sagging, but of course, greatly increases the number of joints. It is, finally, necessary in most of these heaters to use a form of furnace which is difiicult to build, greatly increases the size of the device and is otherwise un-- economical.

Seeking to avoid these numerous objections I have devised a form of pipe heater which greatly economizes space, requires much less space for the heating surface, and is in other respects more economical and vmore readily operated. To this end I arrange the heating surface on top of the furnace whereI place a plurality of banks of tubes constructed of steel with a cast iron corrugated surface, after the manner of the well known Foster superheater tubes,

and the roof of the furnace I construct of bare tubes encased or embedded in special fire brick blocks similar to the encircling tile used in certain forms of water tube boilers with horizontal bafiing. This obviates the trouble usually' encountered with arched roof construction, and is useful in cooling the hot gases by absorbing the radiant heat.

The corrugated casings do not cover the entire length of the tubes, and the ends of these tubes are plain. To each of such ends and abutting against the ends of the corru gated' casings is fitted a rectangular metal plate, by means of which the tubes can be built up on each other and all supported at the bottom by suitable means so that any tube may-be removed without disturbing the others These rectangular plates form the inside wall of the chamber heating surfaces.

The ends of the tubes projecting beyond and through this wall, and which, as has been stated are plain, are connected by return headers of cast steel fitted with hand hole plugs. The length of the bare ends is greater than necessary for normal requirements, and they are expanded into the return headers. This admits of the ends of the tubes being cut 0E, in case' it becomes necessary to remove and replace a header, and again expanded into another header. Were it not for this, a new tube would have to be furnished, whenever it becomes necessary to replace a return header.

A further object of the present invention resides in the provision of a system of oil heating conduits so arranged that one set of containing the conduits receives substantially radiant heat I only. To prevent overheating and excessive disassociation of the oil in these conduits they are preferably provided with suitable el ements to temper the direct effect of the high ly intense radiant heat rays developed in the furnace'chamber. The elements for shielding these conduits preferably but not necessarily comprise coverings of refractory material. The elements are preferably so disposed and arranged with respect to other parts of the apparatus that the hot gases of combustion are prevented from traversing across and around the tubes or conduits and in this way provision is made for preventing the imparting of heat to the conduits from the hot gases. Thus the accumulative heatmg eflects of heat of convection and heat absorbed by radiation are avoided and overheating is prevented. In addition to the first mentioned set of conduits I employ an other set preferably shielded from the direct radiant heat rays in the furnace chamber and disposed in the path of the hot gases of combustion. Upon these last mentioned conduits there are provided metallic casings preferably of cast iron and preferably corrugated. The heat absorbing surfaces of these conduits are preferably proportioned approximately to the temperatures of the gases sweeping'over the same whereby the rate of heatabsorption of the oil is substantially equalized and whereby excessive heating and disassociation of the oil flowing therethrough is prevented. Furthermore, the heat absorbing surfaces are proportioned in accordance with the rate at which the oil may properly absorb heat from the hot gases. The casings are so arranged and disposed and the surfaces are of such extent and so proportioned that excessive ab.- sorption of heat in certain conduits thereby-causing excessive disassociation of theoil and the formation of excessive amounts of carbon and gas is prevented. Furthermore the casings also provide against an ineflicient and low absorption of heat by the oil flowing through other conduits.

Further objects and advantages of my improved construction will be hereinafter pointed out in the accompanying specification and claims and shown in the drawings which, by way of illustration, show a preferred embodiment of my invention.

I have devised other features of novelty in the heater whichwill be described in detail hereinafter by reference to the accompanying drawing, in which,

Fig. 1 is a vertical longitudinal sectional view of the heater.

Fig. 2 is a vertical cross section of the 5 same.

Fig. 3 is a cross sectional view partly in elevation of a heater with a special improve -ment incorporated therewit v Fig. 4 is a section of a portion of Fig. 2, at right angles to the plane of that figure.

Fig. 5 is a view in elevation and on an enlarged scale of the ends of the tubes.

Fig. 6 is a longitudinal .view partly in elevation of some of said tubes.

The general arrangement of the heater is best shown in Fig. 1, in which the walls of the setting are indicated by the numeral 1. The furnace of fire chamber 2 is at the bottom and is roofed over by the oil pipes 3, laid horizontally and parallel and embedded or encased in fire brick blocks 4.

Over this roof are beams 5 which support cross beams 6 for supporting the tubes. The latter are shown as grouped in three banks. Each tube or pipe 3 is surrounded with corrugated rings 7 up to points near their ends, where they are fitted with rectangular cast iron or other plates 8, beyond which the relatively long bare ends extend. These pipes are supported in their banks by means of the rectangular end plates 8 as shown in Figs. 1 and 5, and these plates form the wallsof the heating chamber. The bare ends are connected in series in each bank by cast steel return headers 9 into which the ends of the tubes are. expanded, and in line with each pipe is a hand hole closed by a conical plug 10 drawn against acopper ring seat by a screw 11.

The end plates 8 are preferably flanged as shown in Fig. 6 and at the corners are cut away to form, when the pipes are super: posed, rectangular openings through which means may be introduced for cleaning the exterior of the corrugated pipes of soot or the like should this become necessary.

The hot gases from the fire follow the path indicated in Fig. 1. The radiant heat is absorbed by the fire brick covering for the horizontal pipes and the gases thus cooled pass upwardly and then horizontally back over the banks of tubes to the flue 12 which may contain a damper 13.

The oil is introduced into the horizontal ill encased pipes at the right or part furthest removed from the fire. It is forced in series through these pipes and out through a vertical pipe 14, to the top of the first bank of tubes. Through these it passes in series and is thence carried to. the top of the second bank and so on to the outlet 15. In thisway a perfect countercurrent of oil to the flow of hot gases is secured, much more effectively and perfectly than many other form of heater ofwhich I am aware- The flanges or corrugations of the first bank of tubes, that to the right in Fig. 1, are not as deep as in the other banks. This is because the gases sweeping this bank are hotter than those which pass the others and a less extended heating surface is therefore required at this point for securing the best heating effects on the oil. tents of the heating surfaces are not of the essence of the invention, butshould be approximately as shown in Fig. 6,where the upper pipe isshown with the more ex tended surface and the lower pipe with the corrugations of lesser depth.

To gain ready access to the return headers and hand holes, suitable doors 16 in the sides of the setting are provided. Through these any hand hole plugmaybe removed and the interior of a pipe examined, or any pipe section may be detached .and removed.

I have revised in connection with this heater a means by which the distillates can be taken off at different temperatures or at different points during the progress of the oil through the heater. This is shown in Figs. 3 and 4;. The oil passing, for instance, through the first section or bank of tubes enters one of a series of horizontal tanks 17 at the top of the device through a connection 18 with the bottom of the tank. The

oil 'risest'o a certain level in the tank and is passed on to the next bank of tubes by a connection 19 from the bottom of the tank but at its opposite end.

In the top of'the tank and near the end at which the oil leaves a pipe connection 20 is provided for carrying off the vapors which may have been evaporated in the first bank. If this opening, were not controlled, it is possible that a stoppage of circulation in the second bank would cause the oil to circulate through this vapor outlet resulting in the burning out 'of the tubes in the bank or banks in which the flow of oil is stopped. I therefore provide a valve21 for this outlet controlled by a float22, so that when the oil: level rises to a certain point the outlet is automatically .closedv and .as more oil is pumped through the first bank, and into the tank the pressure increases and this increase would tend to flow outany stoppage in the succeeding bank,

The advantages of the above described than with bare tubes.

The relative. eX-* ized as follows:

Less space is required for a given heating surface, and hence fewer joints are needed A shorter path of travel for the oil through the heating surface is provided and less pressure for circulating the oil is required. The construction affords greater accessibility for inspection, cleaning and repairs, it eliminates all the troubles ordinarily met with in flanged joints, gaskets and bolts; it secures an air tight setting; it permits tubes to be removed and replaced without disturbing any others; it reduces the fire risk because all joints are outside the lining of the chamber containing the heating surface; and it eliminates all danger of the tubes burning out. In addition to these is the great advantage resulting from the perfect countercurrent feature to which the construction so readily lends itself, and the possibility of using separators by which distillates can be taken off at different temperatures.

A further and peculiar feature of value in this invention results from the weight and thickness of metal in the construction of the tubes or elements. Oil is extremely sensitive to changes in temperature, and it is therefore most important that it be uniformly heated. A slight increase in. temperature for a short period may completely the said pipes to control the absorption of heat by the oil and prevent the disassociation of oil therein, and banks of oil conducting pipes having heating surfaces thereon through which the oil flows after passing through the firstmentioned pipes, said last mentioned-banks being disposed in thepath of the hot gases from the furnace chamber;

2. In an oil heater, the combination with. a furnace chamber and a chamber through which the hot gases pass, of oil heating tubes receiving heat by radiation but protected from intense radiant heat by blocksof refractory material located in the first on furnace chamber, said refractory material being adapted toprevent the disassociation of the oilcontained in the said tubes, said tubes also having provisions associated therewith to prevent hot gases of combustion from traversing across and around the tubes and thereby prevent the excessive transfer of heat by convection from said gases thereto, and oil heating tubes connected with the first mentioned tubes and located in the path of the hot gases passing through the second chamber.

3. In an oil heater, the combination with a chamber through which the hot gases pass, of a bank of tubes, rectangular plates fitted to said tubes near the ends, which ends projectthrough said plates, the plates forming the walls of such chamber, and headers joining the free ends of the tubes in series by connection with the same, independent of the plates, as herein set forth.

4:. In an oil heater, in combination, a furnace chamber and a tube chamber, a bank of oil conveying tubes in said tube chamber, said bank of tubes being shielded from the direct rays of highly intense radiant heat developed in the furnace chamber, a passage connecting the furnace and tube chambers and adapted to direct hot gases from the furnace chamber to the tube chamber where the said gases sweep the tubes, a plurality of metallic casings completely encasing such ortions of the tubes which are swept by t e hot gases, said casings having the heat absorbing surfaces thereofsubstantially proportioned in accordance with the temperature of the hot gases sweeping thereover whereby rates of heat absorption by the oil flowing therethrough is substantially equalized and whereby overheating of the oil and excessive disassociation of the same is prevented.

5. In an. oil heater, the combination of a plurality of banks of tubes exposed to the hot furnace gases, each tube having fitted to it near its end a rectangular plate which when the tubes are assembled form the walls of the heating chamber, and headers joining the tubes of each bank in series and'connected to the free ends of said tubes which extend through the rectangular plates, said headers being independent of and at a distance from the said rectangular plates.

6. In-an oil heater, the combination with banks of tubes exposed to the hot furnace gases, of rectangular plates fitted to each tube near its end and which when the tubes are assembled form the walls of the heating chamber, each of said plates having its corners cut away to form holes through the said chamber wall. 1

7. In an oil heater the combination with a furnace, of a roof composed of oil conducting pipes encased in blocks of refractory non-metallic material adapted to prevent the overheating of the oil under intense heat in said furnace, a heating chamber disposed above thlefur'nace, and a plarality of banks of tubes therein connected in series with the tubes in the furnace roof in such a manner that the fiow of oil therethrough will be counter to the flow of the hot gases sweeping the same.

8. I'I'1 an oil heater the combination with a furnace and a heating chamber through which the hot gases pass, of banks of steel tubes in said heating chamber, each tube enveloped in a cast iron corrugated casing covering the central part of the tube, and rectangular plates fitted to the tubes at the ends of the corrugated casing to form the walls of the heating chamber, the projecting bare ends of the tubes being connected together independent of said plates.

9. An oil heater comprising a furnace chamber and a tube chamber connected to permit the transfer of hot gases from the furnace chamber to the tube chamber, a plurality of oil conveying tubes in the tube chamber, said tube and furnace chambers being so arranged that the tubes in the tube chamber are shielded from the direct highly intense radiant heat developed in the furnace chamber, a plurality of casings on said tubes arranged to completely encase and protect the parts of the tubes which are swept by hot gases, said casings having heat absorbing surfaces of varying extents substantially coordinated to the tem perature of the gases sweeping thereover and with the casings provided with the greater extents of heat absorbing surfaces disposed at points most remote from the furnace chamber whereby the rate of heat absorption by the oil is substantially equalized and whereby overheating of the oil and extensive disassociation thereof is prevented.

10. In an oil heater, the combination with a furnace, of two series of pipe units therein, the first series being exposed to radiant heat and provided with coverings to protect the tubes and the oil contained therein against excessive heating and excessive disassociation of the oil, the other unit being located in the path of the flow of hot gases and having heat absorbing surfaces comprised of corrugated cast iron casings entir'ely encasing the parts of the same in thepa-th' of hot gases, said surfaces being proportioned with reference to the temperature-of the gases which pass over them. and .being adapted to entirely prevent direct accessof the hot gases to the tubes, said surfaces being adapted to .controlthe rate of heat transfer to the oil contained inthetubes to thereby prevent overheating of the oil.

, 11. In an oil heater, the combination with a chamber throug. which the hot gases pass, of abank of tubes, corrugated casings surrounding said tubes up to the walls of said chamber, the ends of the tubes extending through and beyond said walls for an appreciable distance, and being unpro vided with corrugations over said exten-- sion, and return headers connecting the said extended ends of the tubes, said ends be- ,ing expanded into the headers.

12. In an oil heater, the combination with a chamber through which the hot gases pass, of a bank of tubes in said chamber, rectangular plates fitted to the same near their ends and forming, when the tubes are assembled, the walls of such chamber, and return headers into which the ends of the tubes are expanded, the said ends of the tubes extending through and beyond the said plates for an appreciable distance so that they may be cutoff and expanded into other headers when the first named headers are removed or replaced.

13. In an oil heater, the combination with a furnace, of two series of pipe units therein, the first series being exposed to radiant heat and provided with coverings to protect the tubes and the oil contained therein against overheating thereby, the other unit being located in the path of the flow of hot gases and having heat absorbing surfaces comprised of'corrugated cast iron casings entirely encasing the 'parts of the same in the path of the hot gases, said surfaces being. proportioned with reference to the temperature of the gases which pass over them and being adapted to entirely prevent direct access of the hot'gases to thetubes, and connections between said tube units adapted to permit a flow of oil through said units, counter to the flow of gases over the same.

14. In an oil heating apparatus, in combination with a plurality of conduits adapted to'receive the oil to be heated, a plurality of metallic casings completely encasing said conduits'and having the heat' absorbing surfaces thereof proportioned according to the temperature of the hot gases sweeping over said conduits, and also .proportioned in accordance with the rate at which the oil may properly absorb heat without excessive disassociation thereof and without the formation of excessive quantities of gas and carbon.

15. In an oil heater, the combination with a furnace and a heating chamber through which the hot gases pass, of banks of steel tubes in said heating chamber, rectangular plates fitted directly to said tubes adjacent the ends thereof, said plates being superimposed upon each other to form the walls of the heating chamber, corrugated cast iron casings on said tubes and covering the portions of the same from one rectangular plate wall to the other, which are exposed to hot gases, and headers joining the projecting ends of the bare tubes outside of the rectangular plates for the purposes set forth. i

16. In an oil heater, the combination with a furnace chamber through which hot gases flow, of a plurality of steel tubes within said chamber, corrugated cast iron casings upon said tubes, rectangular plates having openings therein corresponding to the outer diameter of the tubes so as to fit directly thereon at any desired points on the tubes which are not provided with corrugated casings, the aforesaid tubes projecting beyond the said plates, said plates forming the walls of the heating chamber, the aforesaid corrugated casings on the said tubes covering the same from one plate side Wall to the other, the said corrugations on the tubes nearest the furnace being of lesser dimensions than those on the other tubes to secure reduced heating surface in the regions of hottest gases, and means for conducting the medium to be heated from tube to tube.

17 In an oil heating apparatus, in combination with a plurality of conduits adapted to receive the oil to be heated, a source of high intensity heat, certain of said conduits which would otherwise be exposed to high and intense heat of radiation being completely encased in coverings of refractory material to cut down the rate of heat absorption by the oil flowing; through said conduits, a plurality of inetallic casings completely encasing such parts of other of said conduits which are swept by the hot gases, said casings having the heat absorbing surfaces thereof proportioned in accordance with the temperature of the hot gases sweeping thereover, said casings with their proportioned heat ab sorbing surfaces and said refractory coverings on the other of said conduits coo erating to equalize the rate of heat abs rption by the oil flowing through different parts of the apparatus and also operating to prevent excessive heating of the oil and the excessive disassociation thereof.

18. In a heatingapparatus for heating oil and the like, the combination of a plurality of chambers, one of said chambers being a furnace chamber, and the other i being a tube chamber, of a bank of heat absorbing tubes in said second or tube chamber receiving heat by convection from .the stream of hot gases passing therethrough in a direction transverse of the tubes, of other heat absorbing tubes receiving heat by radiation from the furnace chamber and having refractory material disposed to shield the sameand prevent circulation of the hot gases around the said .tubes'whereby-the excessive overheating of proportioned substantially in accordance with the temperature of the hot gases so that the casings which are swept by gases of'lower temperature are provided with a from the stream of hot greater extent of heat absorbing surface than those which are swept by gases of l higher temperature, said surfaces being also proportioned in accordance with the rate at which the medium to be heated may absorb heat withoutdisassociation thereof.

20. Ina heating apparatus for oil and the like comprising in combination with a furnace chamber in which intense heat is developed and a tube chamber through which a stream of hot gases from the furnace chamber passes, conduits adjacent the -.roof of. the furnace chamber so disposed and arranged as to prevent. the circulation of'hot gases transversely across and around all sides of the same whereby the substantial transfer'of heat thereto by convection I gases is prevented, and other conduits in the tube chamber connected to the first mentioned conduits and receiving heat by convection from the stream of hot gases traversing said chamber, said last mentioned conduits having heat absorbing casings thereon provided with surfaces of varying extents substantially coordinated to the temperature of the gases passing thereover and to the rate at which the oil or other medium may properly absorb heat. 1

21. An apparatus for heating oil comprising a plurality of conduits disposed in a chamber which is traversed by a stream of hot gases, means for admitting the oil to be heated thereto, a plurality of metallic casings on said conduits covering the same and preventing direct access of the hot gases to the exterior thereof, said casings having variable heat absorbing surfaces proportioned substantially in accordance with the temperature of the hot gases sweeping thereover and with greater extents of such surface in regions of lower gas tempera ture, said surfaces being further arranged and proportioned to accord with the rate at which the-oil within the conduits may properly absorb heat to thereby prevent excessive disassociation of the oil and excessive formation of gas in certain conduits and an inefficient and low absorption of heat by the oil in other conduits.

In testimony whereof I hereto afiix my signature.

JOHN PBIMROSE- 

